ISO/TC 211 Multi-Lingual Glossary of Terms (MLGT)

inner product <vector geometry>

bilinear, symmetric function from pairs of vectors ${\displaystyle {\overrightarrow{v}}_1\to R}$ to a real number such that ${\displaystyle \overrightarrow{v}=\parallel \overrightarrow{v}\parallel }$ and ${\displaystyle {\overrightarrow{v}}_1=\parallel {\overrightarrow{v}}_1\parallel \parallel {\overrightarrow{v}}_2\parallel \cos \theta }$ where "${\displaystyle \theta }$ " is the angle between ${\displaystyle {\overrightarrow{v}}_1}$ and ${\displaystyle {\overrightarrow{v}}_2}$ .

[SOURCE: ISO 19107:2019, 3.54]